Fusion of multi-voltage digital radiography images based on nonsubsampled contourlet transform

In order to increase the single digital radiography (DR) image information of the composite component in the industry, the different DR images are captured at different voltages so as to get the structural information at different thickness region firstly. Secondly, the original DR images are decomposed by nonsubsampled contourlet transform (NSCT), and the low-frequency subbands are fused by the role of principle component analysis (PCA), and the modified central energy role is used to carry out the high-frequency directional subbands fusion. The false edges are extracted, and the values of the high-frequency subband coefficients of the false edges are set to be a small value so as to reduce the false edges in the fusion image. Finally, the output image can be obtained by inverse nonsubsampled contourlet transform. The experimental results show that the fused DR image brings more detailed information, and the structure of the component can be seen clearly, so it is useful to the fast and accurate quality judgements of the component.